Most of the stuttering I have seen people have and the one I have is at the start of words where you can't pronounce the first letter. But after a Google search (I'm not a doctor please ask a professional) maybe it's palilalia? Check this video to see an example of palipalia at 1:28 which is very similar to the one you described https://youtu.be/qB9AslGmgJE And this Wikipedia page for [Palilalia](https://en.m.wikipedia.org/wiki/Palilalia) I hope this helps